What a time to be alive ...
Kids these days have it so much better than when I was coming up. The era of digital, modelers and meticulous crafting by dedicated people makes getting great tone trivial.

I started playing guitar in the early-ish 1980's, and I spent a lot of time (and $$$) chasing the sounds of my idols.
I bought GFPM[1] magazines because they usually had 3 or 4 fully tabbed transcriptions, as well as great interviews.
But one wicked cool feature was an adjunct to one of their featured artists and transcribed songs that had a diagram of the signal chain that the artist used.
A block diagram of effects (pedals) and how they were set so you could replicate their tone (aka "The SOUND"). I studied those and bought a lot of pedals to try to sound like Warren DeMartini, or George Lynch, or ... well everyone wanted to sound like Eddie.
But it never really could replicate their sound on record.
A lot of reasons, mainly being that that era was all analog, and there was no power sinks, so to get that sound as on the record, it meant you needed big ass tube amps, 4x12 cabinets, and (usually a Shure SM57) mics on the speaker into a low noise analog mixer board with some wicked studio effects like real plate reverbs, preamps and EQs that could shape tones.
And Eddie? He used 60's vintage Marshall Plexi amps with the aforementioned 4x12 cabinets loaded with Celestion speakers. But he used a Variac, a device to change (increase/decrease) the AC power going into the amp, cranking the voltage, as well as increasing the tube bias, things that give that sweet vintage Van Halen tone (but boy howdy is it hard on the tubes, he went through them like water in that era).
No, to replicate that required volume levels that would destroy your hearing. No amount of pedals would get you that. You could get close enough to fool yourself, but to NAIL the sound? Nah.
I like to refer to that era as "Turning money into noise", and it was. I spent a lot of my much dearer at the time dollars on amps, effects and the like.
Note: Steve Vai in this era had literally tens of thousands of dollars in rack mounted effects, a rig that was known as a "Bradshaw". I lusted to have that sort of cash, but alas, it was well out of my reach
In the early 2000s that changed. Line 6 released DSP driven modeling effects, and suddenly you could get surprisingly good sounds without a shit-ton of effects. And since then, it has just got better.
Lately, IK Multimedia, the people behind the Amplitube software amp simulation, have released for their platform a series of three Van Halen brown-tone[2] era sounds.
And they are fucking amazing. Alas, I am no longer chasing that VH1 thru 1984 Eddie sounds (and there were plenty of different variants. Purists insist that the original album was the pinnacle of Eddie's sound, but bollocks) so I am not really interested in spending the relatively modest amount of money for a Tone-X pedal, and the $100 tone packs to get these.
Still, watching Cam Cooper demo this, with his deftness in playing Van Halen riffs gives me chills.
Grab a beverage and watch these to be truly impressed by the fidelity to the original master.
Alas, I am not going to rush out and buy these. But if I was magically 19 years old again, I would be selling my soul to grab this. Back then I had a shitty Crate amp, and an Ibanez that I couldn't keep in tune to save my life.
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1 - Guitar for the Practicing Musician
2 - not to be confused with the "Brown Sound"